Aspirin should be added to anticoagulation for patients with prosthetic heart valves - a cochrane review

. – Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism. Oral anticoagulation alone, or the addition of antiplatelet drugs, has been used to minimise this risk. An important issue is the effectiveness and safety of the latter strategy. This is an update of our previous review; the goal was to create a valid synthesis of all available, methodologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves. Adding antiplatelet therapy, either dipyridamole or low–dose aspirin, to oral anticoagulation decreases the risk of systemic embolism or death among patients with prosthetic heart valves. The risk of major bleeding is increased with antiplatelet therapy. These results apply to patients with mechanical prosthetic valves or those with biological valves and indicators of high risk such as atrial fibrillation or prior thromboembolic events. The effectiveness and safety of low–dose aspirin (100 mg daily) appears to be similar to higher–dose aspirin and dipyridamole. In general, the quality of the included trials tended to be low, possibly reflecting the era when the majority of the trials were conducted (1970s and 1980s when trial methodology was less advanced).